refactor: updated socket.io, this fixes an issue with admin/songs

frontend/dist/index.tpl.html

@@ -39,7 +39,7 @@
 	<script src='https://www.youtube.com/iframe_api'></script>
 	<script type='text/javascript' src='/vendor/moment.min.js'></script>
 	<script type='text/javascript' src='/vendor/can-autoplay.min.js'></script>
-	<script type='text/javascript' src='https://cdnjs.cloudflare.com/ajax/libs/socket.io/1.4.8/socket.io.min.js'></script>
+	<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.2.0/socket.io.js" integrity="sha256-yr4fRk/GU1ehYJPAs8P4JlTgu0Hdsp4ZKrx8bDEDC3I=" crossorigin="anonymous"></script>
 	<script type='text/javascript' src='/lofig.min.js'></script>
 	<script>
 		(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){